Neural cultures

Abstract

Production of fully differentiated, optionally immortalized, neural cells—by enhancing replication then inducing differentiation by mimicking cell's natural environment in vitro. The cells are useful for transplantation or drug screening.

What is claimed is:  
     
       1. A method for producing a homogeneous population of neural cells which method comprises: 
       a) enhancing the replication of an undifferentiated first neural cell with an immortalizing oncogene including, or having associated therewith, a control means responsive to temperature; and  
       b) exposing said replicated first neural cell of step a) to an environment by an in vitro incubation step which is selected from the group consisting of:  
       (i) incubation in the presence of mitotically active primary cells obtained from the same region of the central nervous system from which said first neural cell came; and  
       (ii) incubation in the presence of an extract of mitotically active primary cells obtained from the same region of the central nervous system from which said first neural cell came:  
       said incubation of said neural cell being carried out to produce fully differentiated active neural cells, committed to a single neural phenotype, but maintaining any replicative drive of undifferentiated neural cells by not raising the temperature to a non-permissive temperature of said oncogene control means.  
     
     
       2. A method according to  claim 1  wherein said primary cells are removed from said neural cells when said primary cells reach confluence. 
     
     
       3. A method according to  claim 1  wherein said replicated neural cells are exposed to a soluble extract from said primary cells. 
     
     
       4. A method according to any preceding claim wherein said primary cells are from the same species as said first neural cell. 
     
     
       5. A method according to  claim 1  wherein said environment is from a different species to that of said first cell. 
     
     
       6. A method according to  claim 1  wherein said oncogene is SV40T. 
     
     
       7. A method according to  claim 1  which further includes transforming said first neural cell with a safety feature gene which is either constitutive or can be selectively activated so as to enable, in either case, selective disabling or destruction of said differentiated cells. 
     
     
       8. A method according to  claim 1  wherein replication step a) is carried out in a medium including at least one added growth factor. 
     
     
       9. A method according to  claim 1  wherein incubation step b) is carried out in a medium containing at least one added growth factor. 
     
     
       10. A method according to  claim 1  wherein differentiation occurs in a medium containing at least one added growth factor.